Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Natural Calamities: These are sudden natural events like floods, droughts, and cyclones that cause widespread destruction of life and property.
Floods: A condition where dry land gets submerged under a large amount of water, usually caused by heavy rainfall, overflowing rivers, or bursting of dams.
Droughts: A prolonged period of little or no rainfall, leading to a severe shortage of , crop failure, and famine.
Cyclones: Violent storms that originate over oceans due to low-pressure conditions, characterized by high-speed winds rotating around a center called the 'Eye'.
Water Scarcity in Droughts: During droughts, the groundwater level drops significantly, and the rate of evaporation () exceeds the rate of precipitation ().
Soil Erosion: Floods lead to the washing away of the fertile topsoil, which can be represented by the loss of organic matter and minerals.
Rainwater Harvesting: A method to prevent droughts by collecting and storing rainwater for future use, maintaining the balance in the soil.
📐Formulae
💡Examples
Problem 1:
During a heavy storm, the wind speed reaches and the air pressure at the center of the storm is very low. Identify the calamity.
Solution:
Cyclone.
Explanation:
Cyclones are characterized by high-speed winds and a low-pressure center (the 'eye') that develops over warm ocean waters.
Problem 2:
A region receives rainfall for two consecutive years. What will happen to the level of in the wells?
Solution:
The level will deplete or the wells will dry up.
Explanation:
Without rainfall (precipitation), the groundwater is not recharged, leading to a drought where the water table drops significantly.
Problem 3:
Why is afforestation (planting trees) recommended to control floods?
Solution:
Trees act as a barrier and increase soil infiltration ().
Explanation:
The roots of trees hold the soil together and help the ground absorb water, reducing the surface runoff that causes floods.